gdb can use the MIPS remote debugging protocol to talk to a MIPS board attached to a serial line. This is available when you configure gdb with ‘--target=mips-elf’.
Use these gdb commands to specify the connection to your target board:
gdbwith the name of your program as the argument. To connect to the board, use the command ‘target mips port’, where port is the name of the serial port connected to the board. If the program has not already been downloaded to the board, you may use the
loadcommand to download it. You can then use all the usual gdb commands.
For example, this sequence connects to the target board through a serial port, and loads and runs a program called prog through the debugger:
host$ gdb prog gdb is free software and ... (gdb) target mips /dev/ttyb (gdb) load prog (gdb) run
gdb also supports these special commands for MIPS targets:
set mipsfpu double
set mipsfpu single
set mipsfpu none
set mipsfpu auto
In previous versions the only choices were double precision or no floating point, so ‘set mipsfpu on’ will select double precision and ‘set mipsfpu off’ will select no floating point.
As usual, you can inquire about the
mipsfpu variable with
set timeoutseconds command. The default is 5 seconds. Similarly, you can control the timeout used while waiting for an acknowledgment of a packet with the
set retransmit-timeoutseconds command. The default is 3 seconds. You can inspect both values with
show retransmit-timeout. (These commands are only available when gdb is configured for ‘--target=mips-elf’.)
The timeout set by
set timeout does not apply when gdb
is waiting for your program to stop. In that case, gdb waits
forever because it has no way of knowing how long the program is going
to run before stopping.
lsitarget. When on, gdb will display warning messages whose codes are returned by the
lsiPMON monitor for breakpoint commands.